Examine source code of MultiBoard

{
  "manifest_version": 2,
  "name": "MultiBoard",
  "version": "1.2",
  "description": "Copy multiple things to clipboard and save them for later",
  "permissions": [
    "clipboardWrite",
    "clipboardRead",
    "storage"
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": true
  },
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": {
      "16": "assets/multiboard-firefox-icon.png",
      "48": "assets/multiboard-firefox-icon.png",
      "128": "assets/multiboard-firefox-icon.png"
    }
  },
  "icons": {
    "16": "assets/multiboard-firefox-icon.png",
    "48": "assets/multiboard-firefox-icon.png",
    "128": "assets/multiboard-firefox-icon.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "multiboard@5nsou.cool"
    }
  }
}